Ok, earth is flat and a disk. Let's see at where does your imagination goes.
I will edit this post when adding new questions.
1. What's on the other side?
2. Earth is a flat disk, is the sun, moon, jupiter or other space objects all flat disks?
If they are, it's real luck that all of them face exactly to the same side so that we can see a circle.
If not, does it means we have 2 different sets of laws that govern the universe?